Safety starter



l Oct. 24, 1950 s, JACQBSEN 2,527,423

SAFETY STARTER Filed Jan. 27, 1948 W- ll- A'ITORNEYS Patented ct. 24, i950 UNITED STATES PATENT OFFICE 2,527,423 SAFETY STARTER Irwin S. Jacobsen, Little Falls, N. J., assigner to Industrial Electronics Corporation, Nwark; N. J a corporation of New Jersey `7 Application January 27, 1948; SerialfNo. 4,603

11 Claims. 1

The present invention is concerned with safety starting devices and with circuits incorporating the same for the protection of gaseous electric discharge equipment such as fluorescent lamps of the hot cathode type.

It is among the objects of the invention to provide a safe-ty device of the above type which is relatively inexpensive, compact and economical in operation, requiring a minimum of parts, allor which are contained in a single sealed unit and which lends itself for use with fluorescent lamps andthe conventional fixtures thereof as a replacement for starters of conventional type, which device utilizes but a single resistance to control the safety action and when incorporated in a starting circuit does not draw current when thela-mp isffunctioning normally and which operates dependably and promptly without iioating between the contacts thereof to preclude the repeated application of starting current to a defective lamp and to `avoid the annoyance of continuous flashing of the defective lamp after the iirst few starting impulses have been applied thereto and which automatically restores itself, promptly to permit normal operation of a new lamp substituted -for the defective one, and the eili'cacy of which is not affected by variations in the ambient temperature, thereby safeguarding the lamp from the destructive effect of repeated a glow switch starter having a conventional bi- I metallic larm which forms one of the electrodes thereof, aheat responsive switch arm whichv functions as the other electrode of `the glow switch starter, anda safety resistor which is connected at one end to said heat responsive switch arm.

The safetyv starting device is connected with the bimetallic arm thereof `in series with one of In -the embodiment herein shown, the safetyy resistor iis in circuit only when `it -is attempted to operate a defective lamp and remains {outof circuit at all othery times throughoutfthe ope-ration of a normally functioning-lamp.

*In response to the heat evolvedlin the hulbfby the fglow inthe. gapy between the 4twoy electrodes,v

29o-113.5) 2 after repeated` attempts of the glowsw-itch starter tostart a defective lamp, the switch arm will be displaced, thereby removing the short circuit from the safety resistor immediately to bring it into action. The heat evolved inA the gap and' in the safety resistor will continue to displace' Inv the accompanying drawings in which areV shown one vor more Aof various possible'emhodiments ofthe several features of the invention,

Fig. .1 isa 4view of-y thesafety starting vunit in:

longitudinal crossr section,

Fig. 2-isa vfragmentary. perspective view on .a1

larger scale of the unit with the casing removed,

Fig. I3 iis Aa viewlsimilar .to Fig. 210i vanother embodiinent of the-device, and

Fig. 4 lis a circuitdiagram showing `.the safety starter circuit common' to both embodiments .f herein. l f

Referring now to the drawings, there is shownin the diagrammatic view of Fig. 4 a conventionalfgaseous electric discharge device rIElof the` hot cathode vtype such as a fluorescent lamp-including a pair of electrodes Il and |2 at opposite ends thereof. One of the mains i3v con the other main I,thel`atter being connected to electrode I 2. I

The safety starting device Il which is ineor-' poratedinthe starting circuit has all of itsele-r ments contained ina` glass envelope ory bulb IWB filledl with an'inert gassuch as neon. 'lhedevice'y has a pair of terminals t9 and 2l which areV con-f nected'to electrodes Hand l2, respectively, ofi-the lamp lby leadslrZ'and y23. M

The safety device' l1 comprises a starter 25" preferably ofthe glow switch type, onev of the electrodes of which, preferably the bimetallic arm 2li as shown, is connected to terminal why' lead.

The safety device Il also includes a bimetallicswitch arm 27|,one end 28vr ofl whichfis connected to one end ofas-nesistor-Zllfl as at 3l.

contact end 32 of the switch arm 21 is movable between the contact end 33 of bimetallic starter arm 29 and a contact bar 34 connected to the other end of resistor 29 as at 3B and thence by lead 41 to terminal 2I. The contact end 32 of the switch arm 21 normally engages contact bar 34 so that resistor 29 is normally short circuited.

A condenser 35 is provided across terminals I9 and 2l to prevent arcing of the starter contacts when the device is in use.

When switch I is closed, the line voltage will be applied across the electrodes II and I2 of the lamp I0 and across terminals I9 and 2I. As the applied voltage is at the outset insufficient to cause arcing of the lamp I0 but sufficient to cause glow switch starter to ionize across the gap 3D between contacts 32 and 33 thereof, current will flow through the circuit, storing energy in the ballast coil The path of current through the circuit will be through main I6, electrode I2, lead 23, terminal 2l, lead 41 to contacts 34 and end 32 of switch arm 21 `across the gap 39, contact end 33 of bimetallic arm 26 through said arm 26, lead 46 to terminal I9, lead 22, electrode II, ballast coil I4 and main I3. The heat developed by the ionization of the gas in the bulb I8 across gap 36 will bring contacts 32 and 33 together to close the gap 30, thereby stopping the glow. As soon as the glow ceases, the bimetallic arm 26 will cool and deflect, thereby causing the contacts 32 and 33 to separate. This will break the starting circuit through the electrodes II and I2 and the ballast coil 4, causing the energy which has been stored in the latter to discharge through the circuit. This sudden impulse should bridge the gap between the now heated electrodes in the lamp I 0 and start the arc, causing the lamp to light. Since the arc when once maintained requires voltage less than that required to initiate the glow discharge in the gap 30, the glow switch starter 25 will remain out of action and the starting circuit is broken, due to the gap 30 between contacts 32 and 33. If the lamp is in normal condition, one or two cycles of the glow switch should light it.

At the same time that the glow switch starter 25 is ionized, but before the lamp lights, the heat generated by the glow in the gap 30, in addition to causing bimetallic arm 25 to deilect, will also be dissipated to the bimetallic switch arm 21 which is slower acting than arm 26. If the lamp is defective, continued cycles of the glow switch starter 25 will produce suicient heat to increase the temperature in bulb I8 to such a degree as to cause switch arm 21 to deflect so that the contact end 32 thereof is movedout of engagement with contact bar 34, thereby removing the short circuit about resistor 29. The latter will immediately draw current, the circuit being from main I6, electrode I2, lead 23, terminal 21, lead 41, through resistor 29, switch arm 21, contact end 32 thereof, across the ionized gap 30, contact end 33 of bimetallic arm 26, through said arm, lead 46, terminal I9, lead 22, electrode II, ballast coil I4 and main I3.

By reason of the heat dissipated by the current flowing through resistor 29 and the heat caused by the glow in gap 39 bimetallic arm 26 and switch arm 21 will deflect toward each other until the Contact ends 32 and 33 thereof respectively are in engagement, closing gap 39 and placing resistor 29 directly across lamp electrodes II and I2.

Continued passage of current through resistor 29l will produce sufficient heat in the bulb I8 to retain switch arm 21 and bimetallic arm 26 in deflected position and maintain contact ends 32 and 33 thereof together, thus eliminating the gap 39 and effectively removing the starter 25 from the circuit to prevent any further cycling thereof, thereby preventing the fluorescent lamp from starting. It is apparent that the effective removal of the glow switch starter '25 will occur if the lamp does not light after a few cycles. Thus the rapid destruction of the glow switch starter 25, due to many repetitions of the starting cycle on a defective lamp, is avoided. Shortly after the circuit is `broken by the opening of switch I5, resistor 29 will cool and allow switch arm 21 and bimetallic arm 26 to revert to their normal position shown in Fig. 4, in readiness for normal operation with a replacement lamp.

Inasmuch as the bimetallic arm 23 and switch arm 21 require but little heat in order that they be maintained in deflected position, resistor 29 is preferably of high ohmic value so that only a small amount of current will be consumed by the device. Resistor 29 is desirably of carbon, preferably glazed to prevent absorption of the neon or other inert gas in the bulb with changing temperature therein.

Thus when glow switch starter 25 is effectively removed from the circuit by switch arm 21 when the lamp is defective, and resistor 29 is placed across the electrodes I I and I2, the resistor 29 will draw .but little current.

Safety starter units incorporating the starting and safety controls of the circuit shown in Fig. 4 and above described are shown in Figs. l, 2, and 3 of the drawings wherein the numerals used in the circuit diagram of Fig. 4 are employed for corresponding elements. Referring to the embodiment shown in Figs. 1 and 2, the unit, which is connected across leads 22 and 23 from electrodes II and I2 respectively, comprises an insulating base 4I with two terminals I9 and 2| depending therefrom and a metal cover or cap 42 having tabs 43 removably to secure it to base 4I. The cap 42 has an insulating liner 44 covering its side wall and a further insulating liner disk 45 for its top wall. In the unit is enclosed the glass bulb I8 which is filled with a noble gas, such as neon for instance, and has leads 4B and 41 extending through the pinched end 48 thereof which seals the bottom of the bulb. The upper ends of the leads 46 and 41 in the bulb are connected to supports 49 and 5I, respectively, by a drop of glass as at 52. Afiixed to support 49 is a, U-shaped electrode 2B, of bimetallic material responsive to variations in temperature. Ailxed to support 5I is a contact bar 34 spaced from the contact end 33 of bimetallic arm 26. A resistance 29, preferably carbon as shown, but alternatively a wire resistance or the like is affixed at one end to support 5I preferably by soldering and extends upwardly therefrom. The upper end of resistance 29 has a bimetallic switch arm 21 afxed thereto as at 3| and extending downwardly therefrom spaced from the resistance 29 and substantially parallel thereto. The switch arm 21 has a Contact end 32 which normally engages contact bar 34 and is spaced from the bimetallic arm 28.

A capacitor 35 is positioned outside the bulbY and connected across the terminals I9 and 2l by leads 53 and 54 to prevent arcing of the contacts of the unit.

It will be understood that the spring tension of switch arm 21 is such as to maintain the contact end 32 thereof against contact bar 34 even at the highest ambient temperature encountered.

conserve space, is affixed as at 28 to the lowery end of mount 55 and extends laterally therefrom encompassing resistor '29 with the4 contact end 32 of switch arm 2l normally in engagement with Contact bar 34 By this construction the overall length of the" unit may be less, which is an important factor when space is limited.

Thus it can be seen that when the lamp' is operating normally, the safety starting device is completely out of circuit and no current is consumed thereby and with a defectivelamp in cirduit only the resistor 29 draws current and asv its ohmic value is high, will consume but a minimum of current.

The unit is simple in construction, requiring o butfew parts and henc'e'is relatively inexpensive. It is thoroughly reliable in operation, inasmuch as once the switch arm 21 leaves the contact bar 34, resistance 29 will heat to move contact end 32 into engagement with contact end 33 to stop the repeated starting of a defective lamp without danger of hunting or iloating of switch arm 21.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope of the claims, it is intended that all matter contained in the above description or shown in the accompanyingl drawings shall be interpreted as illustrative and not in a limiting` sense.

Having thus described my invention, what I claim as new and desire to secure by Letters Pateintof' the United States is:

1. A safety starting and operatingl circuit, 'con-i' tained in a gas filled bulb for gaseous electric discharge lamps equipped with spaced electrodes,4v

said circuit comprising a glow discharge type starter in said bulb, said starter comprising a pair of starting contacts normally spaced from' each other and forming a gap therebetween, a heat responsive armk carrying one of said contacts, connected at one end in said starting circuit, a heat responsive switch arm in said bulb connected at one end in said starting circuit and carrying the other of said starting contacts, said starter evolving sumcient heat in the attempted starting of a defective lamp for displacement of said switch arm to bring said starting contacts into engagement, thereby closing said gap, and heating means in said bulb, normally out of circuit and connected in series with said starting circuit and said switch arm when the latter has brought said contacts into engagement and closed said gap after said attempted starting of such defective lamp, to maintain said switch arm in displaced condition as long as the operating circuit remains closed.

2. A safety starting and operating circuit, contained in a gas filled bulb for gaseous electric discharge lamps equipped with spaced electrodes, said circuit comprising a glow discharge type starter in said bulb, said starter comprising a pair of starting contacts normally spaced from each other and forming a gap therebetween, a heat responsive arm carrying one of said contacts,

connected atvv one end in saidL starting clrcuit'f? heat responsive switch arm in said bulb in close' proximity to said first named heat responsive` arm, connected at one end in said starting cir'- cuit` and carrying the other of said starting! contacts, a resistor in said bulb in said starting` circuit', normally short circuited-by said switch arm', said starter evolving sufficient heat in the attempted starting of a defective lamp for displacement of said switch arm to remove the short circuit across' said resistor and place the latter inv series withv said starting circuit, and for bringing said starting contacts into engagement, thereby closing said gap, the heat evolved by said resistor maintaining said switch arm in displaced condition as long as the operating circuit remains closed.

3. Asafety starting and operating circuit, contained in a gas lled bulb for gaseous electric discharge lamps; equipped with spaced electrodes, said circuit comprising a glow discharge type starter in said bulb operatively connected in said circuit intermittently to interrupt the latter, said; starter comprising a pair of starting contacts normally spaced from each other and forming a gap therebetween, a heat responsive arm carrying kone of said contacts, connected at one end in said starting circuit, av heat responsive switch arm in said bulb in close proximity to said iirst named heat responsive arm, connected at one end in said starting circuit and carrying the other of said starting contacts, a resistor in said bulb in` said starting circuit and normally short circuited by said switch arm, saidstarter evolving sufficient heatin the attempted starting of a defective lamp for displacement of said switch arm to remove the short circuit across said resistor and place the latter in said starting circuit, and for bringing said starting contacts into engagement, thereby closing said gap and stopping theintermittent interruption of said starting circuit, they heat evolved by' said resistor maintaing said switch.

arm in displaced condition as long as the operat-f ing circuit remains closed.

`A4; A safety starting and operating'circuit, con-1 tained in a gas filled bulb for gaseous electric dis'-y discharge starter means in said bulb operatively connected in the circuit intermittently to interrupt the latter'a heat responsive switch arm in saidbulb, a resistor in said circuit normally shortl circuited by said switch arm, said switch arm, after repeated attempts to start a defective lamp, being deflected by the heat evolved by said glow discharge starter to remove the short circuit from said resistor and place the latter in circuit, said switch arm being further deflected by the continued operation of said glow discharge starter and the heat evolved by said resistor, effectively to remove said glow discharge starter from the circuit, said resistor evolving sufficient heat to maintain said switch arm in deilected position,

thereby stopping the intermittent interruption of circuit, a res'istor in said bulb nor'iiially short circuited by said switch arm, said starter evolving sui'cient heat in the attempted starting of a defective lamp for displacement of said switch arm to remove the short circuit across said resistor and place it in series with said starting circuit, and for bringing the contact on said switch arm into engagement with the contact on said bimetallic arm, thereby closing said gap, the heat evolved by said resistor maintaining said switch arm in displaced condition, effectively to remove the starter from the circuit as long as the operating circuit remains closed.

6. A safety starting and operating circuit for a gaseous electric discharge lamp equipped with spaced electrodes, said circuit comprising heat evolving means automatically to interrupt said circuit to strike an arc between said electrodes, and means to preclude the sustained intermittent starting of a defective lamp, said latter means comprising a thermally operated switch arm in circuit with said heat evolving means and normally disconnected therefrom, a safety resistor in said starting circuit normally short crcuited by said switch arm, said switch arm being deiiected by the heat evolved in said heat evolving means in the attempted starting of a defective lamp to remove the short circuit across said safety resistor, the heat evolved by said safety resistor and said heat evolving means in the continued attempted starting of a defective lamp deflecting said switch arm further into engagement with said heat evolving means, eifectively to remove the latter from the circuit, thereby preventing further attempts to start said defective lamp.

7. The combination set forth in claim 6 in which said resistor alone evolves suicient heat to maintain said switch arm in deflected position.

8. A self-contained safety starter device for a gaseous electric lamp, said device comprising a gas lled bulb having a pair of leads therein extending therefrom, a bimetallic arm in said bulb connected to one of said leads, a resistance in said bulb connected at one end to the other of said leads, a heat responsive switch arm connected at one end to the free end of said resistance, the free end of said switch arm being normally in electrical contact with the opposite end of said resistance and spaced from the free end of said bimetallic arm and movable thereagainst, the space between the free ends of said switch arm and said bimetallic arm forming a glo-w discharge gap.

9. The combination set forth in claim 8 in which a support base is provided having a pair of terminal posts to which the extending ends of said leads are respectively connected.

l0. A self-contained safety starter device for a gaseous electric lamp, said device comprising ak gas filled bulb having a pair of leads therein ex tending therefrom, a bimetallic arm in said bulb connected to one of said leads, an upstanding resistance in said bulb connected at its lower end to the other of said leads, a heat responsive switch arm connected at one end to the upper end of said resistance and extending downwardly and substantially parallel to said resistance, the free end of said switch arm being normally in electrical contact with the lower end of said resistance and spaced from the free end of said bimetallic arm and movable thereagainst, the space between the free ends of said switch arm and said bimetallic arm forming a glow discharge gap.

11. A self-contained safety starter device for a gaseous electric lamp, said device comprising a gas filled bulb having a pair of leads therein extending therefrom, a bimetallic arm in said bulb connected to one of said leads, an upstanding resistance in said bulb connected at its lower end to the other of said leads, a mount aixed to the upper end of said resistance and extending downwardly therefrom substantially parallel to said resistance, a U-shaped heat responsive switch arm afxed at one end to the lower end of said mount, extending laterally therefrom and encompassing said resistance, the free end of said switch arm being normally in electrical contact with the lower end of said resistance and spaced from the free end of said bimetallic arm and movable thereagainst, the space between the free ends of said switch arm and said bimetallic arm forming a glow discharge gap.

IRWIN S. J ACOBSEN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,294,191 Lord Aug. 25, 1942 2,333,215 Thomas Nov. 2, 1943 2,355,417 6 Smith et al Aug. 8, 1944 2,398,128 Zyta Apr. 9, 1946 

